Interim guidelines for wing-in-ground (WIG) craft were approved by the Maritime Safety Committee at its 76th session in December 2002 as MSC/Circ.1054. (Updated by MSC/Circ.1026)
The interim guidelines are intended to provide as much guidance as possible to those involved in the design, construction and operation of WIG craft.
WIG craft - which are not covered by the 1994 or 2000 Code of Safety for High-Speed Craft - are supported in their main operational mode solely by aerodynamic forces which enable them to operate at low altitude above the sea surface but without direct contact with the sea. Accordingly, their arrangement, engineering characteristics, design, construction and operation have a high degree of commonality with those of aircraft.
However, WIG craft operate with other waterborne crafts and must utilize the same collision avoidance rules as conventional shipping. Amendments to the Collision Regulations (Res.A.910(22), adopted by the 22nd IMO Assembly on 29 November 2001) developed by the Sub-Committee on Safety of Navigation, take into account the operational peculiarities of WIG craft.
IMO and the International Civil Aviation Organization (ICAO) have agreed that any WIG craft capable of sustained flight outside the influence of ground effect should also be subject to the rules and regulations of ICAO. Other craft, including those with limited "fly-over" capability, should be covered only by the maritime regulatory regime.
The Interim Guidelines for WIG craft are intended to achieve comparable safety standards to those of the 1974 SOLAS Convention and include relevant recommendations adapted from the 2000 HSC Code.
Significant differences between WIG craft and high-speed craft reflected in the Interim Guidelines include:
- Substantially higher speeds of WIG craft and consequent larger distances travelled in a given time at operational speed;
- The possibility of "amphibious" WIG craft being operated from land base;
- The need for risk and safety levels to be assessed on a holistic basis, recognizing that high levels of operator training, comprehensive and thoroughly implemented procedures, high levels of automation and sophisticated software can all make significant contributions to risk reduction;
- Reduced ability of WIG craft to carry and deploy equipment and systems traditionally associated with seagoing craft;
- Changed use of traditional ship terminology, such as stability, to the safety of WIG craft in its operational mode and corresponding increase in the use of aviation terminology, such as controllability; and
- The capacity of a WIG craft to mitigate hazards associated with its airborne mode by its ability to land on water at any time.
The Interim Guidelines, which apply to craft carrying 12 persons or more, are in three parts:
1. Part A provides general information applicable to all craft;
2. Part B includes prescriptive requirements that may be subordinate to measures developed through the safety assessment recommendations of part C; and
3. Part C details the safety assessments required for all craft.
The Interim Guidelines are intended to be reviewed as necessary to reflect experience gained in their implementation and to further improve the safety of these craft, their passengers and crew.
MSC/Circ.1162 General principles and recommendations for knowledge, skills and training requirements for officers on Wing-In-Ground (WIG) craft is intended to primarily assist Member governments in developing their national requirements for qualification and certification of officers on a WIG craft operating in both displacement and ground-effect modes.
WIG craft definition
A WIG craft is a high speed vessel with features of dynamic supported craft. At the same time, a WIG craft is a flying craft and therefore appropriate provisions of ICAO are also applicable. The WIG craft principal mode of operation is flying through the atmosphere over water or other supporting surface (ground) in the zone of aerodynamic influence of the surface. WIG craft may have amphibious qualities, being capable of travelling over land, ice or snow surfaces (in the transient or service modes of operation).
The WIG craft may be capable of getting over land gradients in order to come out on to specially equipped sites or a sloping shore/bank for loading/unloading operations, small repairs, maintenance, refuelling, etc., as well as for berthing. Transition to principal mode of operation and back is always brought about on water surface. The seaworthiness of a WIG craft depends on its size and is mainly limited by the weather conditions (wind and sea state) consistent with the safe take-off and water landing. The seaworthiness may be practically unrestricted on the flying conditions in the principal mode of operation.
Amendments to the Convention on the International Regulations for Preventing Collisions at Sea, 1972, adopted in November 2001, entered into force on 29 November 2003.
The amendments to existing Rules include new provisions relating to Wing-In Ground (WIG) craft.